Just four months ago, the advice on vitamin D seemed as clear as the sky on a hot summer’s day.

After an exhaustive, five-year review, Public Health England ultimately announced that everyone needed 10 micrograms a day’ in order to protect their bone and muscle health’.

The advice had been a long time coming.

It was based on the recommendations of the Scientific Advisory Committee on Nutrition( SACN ), a team of independent experts set up by the Government to consider all the available evidence and review the decades-old public guidance on vitamin D.

After an exhaustive, five-year review, Public Health England ultimately announced that everyone needed 10 micrograms of Vitamin D a day

Vitamin D is made in the skin by the action of sunlight. In spring and summertime, when the sunlight is sufficiently strong, this is the main source for most people and any excess we make is stored in the fat and liver.

However, these stocks are steadily depleted during the course of its colder months.

And while vitamin D can be found in some food a oily fish, liver, egg yolk and fortified cereals, for example a it’s hard to get enough this style, which is why SACN recommends everyone should take the daily 10 mcg supplement during the course of its autumn and winter.

Those whose skin is rarely exposed to sunlight, such as the elderly, should take this sum every day of the year.

But now researchers writing in the British Medical Journal have thrown a spanner in the works.

After analysing the results of hundreds of trials involving tens of thousands of patients, they concluded there was’ no consistent evidence that vitamin D supplementation improves musculoskeletal outcomes’ if you’re not in the at-risk groups such as older people and certain ethnic groups.

Meanwhile, other experts are now saying that official advice is actually causing some people to take far too much vitamin D, which can lead to a range of serious health problems and may even weaken rather than strengthen bones.

Experts are now saying that some people actually take far too much of the supplement, which can lead to a range of health problems Confounded? It’s easy to see why. So which experts are right a and should you keep taking those vitamin D pills?

The debate has split the medical and scientific communities into those who believe that one in three of the population is insufficient in vitamin D, and sceptics who say supplementation is a’ cure’ for an devised cancer that doesn’t actually exist.

‘We are seeing an over-obsession with something that isn’t a real cancer ,’ tells Tim Spector, a professor of genetic epidemiology at King’s College London and a consultant rheumatologist who runs an osteoporosis clinic at Guy’s and St Thomas’ Hospital, London.

He’s in the sceptic camp, and last week wrote a comment article for the BMJ, in support of the new paper.

‘Now we’ve created this new manner of measuring vitamin D, with arbitrary’ inadequacy’ levels, and abruptly a third of the population is insufficient and you have a whole new industry ,’ he told Good Health.

‘It’s a bit sad genuinely, a modern phenomenon.’

That phenomenon is being helped along by the growth of the home finger-prick blood-test industry.

Levels of vitamin D in the blood are measured in nanomoles per litre. Current NHS guidelines say anything under 15 nmol/ L is’ severe deficiency’ Levels of vitamin D in the blood are measured in nanomoles per litre. Current NHS guidelines say anything under 15 nmol/ L is’ severe deficiency’ Kits cost anything from APS3 0 to APS5 0; you send off your blood for analysis and within a couple of days you receive the result a and, if you are’ deficient ‘, an invitation to buy vitamin D supplements.

Levels of vitamin D in the blood are measured in nanomoles per litre. Current NHS guidelines say anything under 15 nmol/ L is’ severe inadequacy’ and a level of 15-30 is regarded as’ deficiency’.

From 50 to 100 is’ adequate’ and 100 -1 50 is regarded as’ optimal’.

But there is no international agreement.

In the U.S. a reading over 125( which the NHS tells is’ optimal ‘) is regarded as actually being too high a with’ potential adverse effects ‘, tells the National Institutes of Health.

And while the NHS tells vitamin D blood levels shouldn’t fall below 25 at any time of year, the European Food Safety Authority has just define an objective of 50 for everyone.

In other terms, what’s regarded as adequate in the UK, is seen as deficient in Europe.

Professor Tim Spector tells we’ve created a new manner of measuring vitamin D, with arbitrary’ inadequacy’ levels, and abruptly a third of the population is deficient

In fact, tells Professor Spector, all these categories’ were arbitrarily decided by clinical societies and international bodies without consensus’.

He agrees there would’ be some concern’ if someone’s reading was under 20 nmol/ L, but’ true clinical inadequacy’ a where the lack of vitamin D is beginning to affect the bones a probably only occurs when it’s under 10, he told Good Health.

‘There is no evidence that people in the 20 to 50 scope are suffering current problems, and yet that is most of the population currently being labelled as having a disease.’

But Dr Louis Levy, head of nutrition science at Public Health England, indicates the idea that people with these levels are seen as somehow ill is a misinterpretation.

He says that while levels shouldn’t drop below 25, if they did, it doesn’t mean you have a disease a rather it is a level that the majority of the population should achieve, or surpass,’ in order to protect their musculoskeletal health’.

Arguably, that’s a subtle difference most people wouldn’t spot.

Vitamin D is important because it helps the body absorb calcium from food, and a true inadequacy can lead to weak or soft bones a known as rickets in “childrens and” osteomalacia in adults a and can weaken muscles, which, in turn, can lead to falls.

In multiple analyses, low levels of vitamin D have also been linked to a host of other conditions, from diabetes, irritable bowel disorder and arthritis to multiple sclerosis, Parkinson’s disease and even cancer.

Vitamin D is important because it helps the body absorb calcium from food, and a true inadequacy can lead to weak or soft bones

But as yet, there is no conclusive evidence was whether low levels of vitamin D are a cause, or a symptom of these illness, or that taking a supplement will cure them.

In any event, tells Professor Spector, dangerously low levels of vitamin D are find only in situations of rickets and osteomalacia, of which there are only a handful a year.

The NHS recommends that all newborns under a year old should have a daily supplement of 8. 5 to 10mcg, and children aged one to four 10 mcg( newborns on more than 500 ml of fortified newborn formula a day don’t need additional vitamin D ).

No one disagrees with the recommendation that children should receive supplements.

But for the great majority of the population, tells Professor Spector, taking vitamin D’ doesn’t work and is actually distracting people from having a healthier lifestyle, going out in the sunshine and feeing properly’.

Dr Natalie Carter, head of research liaison at Arthritis Research UK, agrees.

The BMJ paper, she tells, is’ interesting, high-quality research which improves our knowledge about optimum vitamin D levels and no doubt during its next review Public Health England will take this study into consideration’.

No one disagrees with the recommendation that children should receive supplements. But for the great majority of the population, tells Professor Spector, taking vitamin D’ doesn’t work’

Clinicians, she tells,’ can’t take a’ one-size-fits-all’ approach when recommending supplementation to prevent vitamin D inadequacy, as the amount needed will vary according to your age, gender, health status and place’ a people who live in more northerly latitudes get less sun.

Arthritis Research UK does not recommend that most peope take supplements, telling:’ The best sort of obtaining vitamin D is through exposure to sunlight.’

MOST ADULTS GET ENOUGH FROM SUN

‘Safely exposing skin to the sunlight for simply 15 minutes per day during the summer months should give you the right amount of vitamin D for the winter months ,’ they say.

This was shown in 2009 by an Australian examine of 120 people who spent a year in Antarctica, where they were deprived of sunlight from March to August.

The study, published in the journal Osteoporosis International, observed those who arrived with vitamin D levels of 100 nmol/ L or higher( achievable with a healthy outdoor summertime lifestyle) “ve had enough” reserves to get through the six months until the sunlight returned.

‘Safely exposing skin to the sunlight for simply 15 minutes per day during the summer months should give you the right amount of vitamin D for the winter months ,’ they say

Last year, a statement by seven specialist UK groups, including Cancer Research UK and the National Osteoporosis Society, said most people who kept their vitamin D topped up in the sunlight in summer’ should[ be able to] keep levels greater than 25 mmol/ l in wintertime even without supplements’.

Indeed, even in the at-risk groups, supplements should be considered on an’ individual basis ‘, said the BMJ authors.

Until July, the advice in the UK on taking vitamin D supplements hadn’t changed for 25 years, and it was categorical: vitamin D supplements were’ not necessary for most of the UK population aged four to 64 years’.

Only those at risk of vitamin D inadequacy a including pregnant and breast-feeding girls, infants, adults over 65 and those with limited exposure and women and children of Asian ethnic origin a should take between 7 and 10 mcg a day.

This recommendation was reviewed, but remained unchanged in 1998 and again in 2007.

Seven specialist UK groups said most people who kept their vitamin D topped up in the sunlight’ should[ be able to] keep levels greater than 25 mmol/ l in wintertime even without supplements’

Then, in 2011 the SACN revisited the recommendations, partly because people were taking heed of advice about skin cancer and biding out of the sun and wearing sunblock; the concern was that they were depriving themselves of sufficient sunlight to produce enough vitamin D.

But there was no evidence of this.

Studies had found that’ although sunscreens can significantly reduce the production of vitamin D under very strictly controlled conditions, their normal utilization does not generally prevent vitamin D synthesis ‘, the SACN concluded.

Professor Spector acknowledges that taking 10 mcg of vitamin D a day will not damage anyone.

‘But my experience is that as soon as you tell people they’ve got to take something they say’ I’ll take more because the more I take the healthier I’ll be’.’

Trials show people with very high levels of the sunshine vitamin are more likely to fracture and more likely to fall over

The problem, he tells, is many people are already feeing foods fortified with vitamin D, such as cereals, bread, milk and yoghurt, and then taking’ dangerously high dosages’ of a supplement on top.

In his clinic, he tells:’ I am now watching people with extremely high levels of vitamin D.

‘They hear the advice and, because they think it’s going to help them, they take what the doctor prescribes them and then go and get a top-up on the internet.

‘In fact, trials show people with very high levels are more likely to fracture and more likely to fall over.’

Indeed it’s easy to discovery vitamin D tablets or capsules containing 20 hours the recommended daily dosage of 10mcg, more than would even be prescribed in the most extreme cases of deficiency.

With very high dosages of vitamin D there is a danger of hypercalcaemia, the build-up of excessive levels of calcium in the blood, which can cause lethargy, high blood pressure, heart problems, hardening of the arteries and kidney damage.

With very high dosages of vitamin D there is a danger of hypercalcaemia, the build-up of excessive levels of calcium in the blood, which can cause lethargy and high blood pressure

In 2014 the Food Standard Agency’s Committee on Toxicity concluded:’ High uptakes of vitamin D from drug or dietary supplements( often over prolonged periods) have caused toxicity in humans, and many cases of such poisoning have been reported’.

It said 110 mcg is the highest amount that could be ingested every day over a lifetime by an adult or child aged 11 to 17 without risk to health( it’s 50 mcg for children aged one to ten, and 25 for infants ).

PILLS WON’T STOP HEART DISEASE

When it comes to what constitutes a inadequacy in vitamin D, gaps in the evidence mean’ we don’t know how low levels need to be to make people genuinely at risk ‘, explains one of the authors of the new BMJ paper, Professor Alison Avenell, clinical chair of health services research at the University of Aberdeen.

She adds the evidence behind the new paper comes from comprehensive systematic reviews of well-conducted clinical trials:’ These indicate vitamin D does not prevent important medical problems such as autumns and fractures in older people.’

So should we all be taking supplements ?

She indicates they’re only needed by people’ who never go out in the sunlight, such as old people in nursing home, and those who rarely go outside or have dres that means they are mostly covered up when in the sunlight, will also be at risk’.

Some research indicates supplements are merely needed by people’ who never go out in the sunlight, such as old people in nursing homes

People with dark skin from African, African-Caribbean and South Asian communities are also in danger’ because their skin will not make vitamin D so effectively in the UK’.

And if you’re not in these groups, and are thinking about taking vitamin D to’ prevent fractures, heart disease, diabetes, or cancer, or many other conditions, we don’t have evidence that it will be helpful’ a in other words, don’t bother.

The authors of the new paper and the NHS do agree on one thing: over the years vitamin D has been credited with being a miracle cure for many conditions but both conclude that there is no evidence taking the pills can help with any non-musculoskeletal condition.

They also agree no one is likely to actually come to grief following Public Health England’s advice to take 10 mcg a day.

As Professor Avenell sets it:’ We suppose few people will benefit and many will take unnecessary supplements.’